The library is the only place I know of. But I know at least the ones I use don't have a big selection.

Audiobooks are a great alternative, but you can also get ebooks. With an ebook you can enlarge the font to be easier for you to read. I also use a black background because it's easier in my eyes.

You can get libby which connects to your entire library through your card, and like the library also free. Audiobooks you listen to through their app, but the ebooks you can either read through app as well or send to your kindle/kindle app.

I’ve only recently run across this Library of Congress program. https://www.loc.gov/programs/national-library-service-for-the-blind-and-print-disabled/about-this-service/?loclr=loc-ppc_s=google_c=visually-impaired-new_ag=pm_kw=books-for-low-vision

Your local library should have a lot. If not they can organise to borrow other books from libraries for you to use.

Also you can borrow ebooks which you can change the font size/font/colour to what suits you best.

Similarly if you have a vision foundation nearby, they usually have a library with various things, including large print.

Visit your local or state library. We have a lot of resources to connect you with. :)

Amazon has a pretty big selection of large print books